Tachometer.



0. ABEREGG.

TAGHOMBTER.

APPLICATION FILED JUNE 20, 1913.

1,075,998. Patented Oct. 14, 1913.

By. J.-

UNITED STQQQES i? OTTO ABEREGG, E BER-NE. SVI'ITZEBLAND ASEIGNGIZ T53 TELEGRAPHEN-WERKSTATTE VON G, I?!

PORATION OF SVJITZEB-LAND.

TAC'HOMETEB.

' predetermined angle during each measuring period, each of these measuring pieces heing adjusted during each inlerval of time by the shaft under test an amount dei'endcnt on the speed of the latter, While the measuring piece which was influenced by this sha it during the preceding measuring e! .1 is

held fast in the position it obtained a: the

end of this eriod and the previously held measuring piece is simnltaneousiy reieased.

A "primary object of my invention is to reduce the Wear of those paris of ihe la-- chometer which are inierrnittentiy engaged during its operation. To this end, I make the measuring pieces the detent in the form of cylindrical tubes, the measuring pieces being rotatable and. axially displaceable on guide-rods and the detent being, jonrnalcd on a rocking arm which is pressed resiliently in the direction of the guide carrying the measuring pieces.

One illustrative embodimentof my invention is represented by way of example in the accompanying drawing, which shows those portions of the mechanism of the inn proved tachometer which are requisiie to explain my inveniion.

In the drawing Figure 1 is a front elevation of the said mechanism as viewed from the righthand side of Fig. 3, Fig. 2 a horizontal section. taken onv the line II- II in Fig. 1, Fig. 3 is a side elevation of the mechanism shown in Fig. 1, and Fig. 4 shows a detail in vertical section and topplan View.

Referring to the drawing, the gear 1, adapted to be operatively connected by suitable means, not shown, with the shaft under test, is positively connected with a driving ban rel 2. ,The toothing on this harrei with a gear 4 fast on the lower en t Specification of Letters Yatent.

Application filed June 20, 1913.

Serial. ism. '2'74 miiirntlr r ioiier.

Mates T (s c in not lw we. r.

tubes haw/in ed rotatahly these rods :1, ity in their low. 1 on the gear is located a 'i(":;ii' phoenix having at ii a guide-hie ing, :iiOWfiWz. .l wmronndin 3. On the plnie 8 10 which a. veriicai and carries at he caui of a late-rail I ing arm a rloxwiivarrl y mien. 1'2. The lai'ter mesh. which on i iiuenced hy draxwsprin, to this segmea being p with ihe rack and the iug a, latter to he pressed firmly onto the plain and prevents it from rising from the same even when there is conside able riijiration The pinion is fast on any in i" a. one end of. which carries a pointer i? movable over a, scaie, not shown.

in the aisle i8 oi the ii vViiiiill The iai ed with a pinion by 1 mediate gee. 21 and Mn.) is jonrnaied in a 'ier 25 which is able to rock about the stationary axle 24 carrying the crownwheel and the gear 21 and, owing: to his carrier being acted on by a helical spring: 26, is ressed against that measuring piece 7 Whlrh is located opnr site to it, so that the said pinion meshes with the it. To keep the measuring piece in its raised position when the gear 4 next rotates, a detent 527 is provided. The latter is analogous in form. to the measuring pieces, i. e. consists of'a tube, toothed on its periphery, rotamhly indented on a vertical pin rising from the fre. end of an arm 28 mounted to rock horihitter and when suitably rotated raises zontally. This eizm is pressed toward the sxie 3 by means of a coil spring 29, whereh I the detcut 27 meshes with that measurii g piecewhich meshed with the pinion 23 during the previous measuring period and comes into gear with the next measuring piece the moment the latter is disengaged from the pinion 23.

The above-described tachometer operates as follows :Owing to the gear 1 being roteted, the spring in the barrel 2 is Wound up and intermittently drives the axle 3 carrying the measuring pieces 7, the pinion 23 being driven by the axle 18 at a speed corresponding to that of the shaft under test. Each measuring piece remains in engagement with, the pinion 23 for a predetermined period, e. the measuring period, 6. g. one second and during this period is raised a distance corresponding to the speed of the shaft under test. That measuring piece -which; is :raised corresponding raises the V plate lfl, and the latter l'ZtISQS the lug 9 and the rack-l2 which rotates the pointer 17.

i When the axle-3 is next rotated the measurmg piece new meshing with the pinion becomes disengaged therefrom, but before suclrdisengagement. occurs, this measuring piece comes into engagement with the detcnt This measuring piece 18 held at the some eievation by the latter during the next measuring period and the pointer 17 therefore remains in the same position. In the ;n2esntime the next measuring piece has been engsiged by the pinion :23 and is likewise raised, 1.. the speed of the shaft under test is higher than during the previous second, this measuring piece is raised to a greater height depending on the difierence in the spwcl, and the pointer 17 is correugly advanced. If, however, the s lower, the measuring piece is not so high, end. does not the plate i and 4}, When. the axis 53 is next .he measuring piece then engaged by the detcnt 27 is released from the latter and therefore falls to its lowest position. The plate 8 simultaneously falls onto the measuring piece immediately following, and the rack 12 therefore fallsan amount corresponding to the difi'erence in the speeds, the pointer being of course brought back. The above series of operations is continually repeated while the tachometer is in operation. As compared with the tachometer described in the above-mentioned patent my improved taehometerhas the advantage that, since both the measuring pieces and the detent are rotatable about their own axes, they wear more uniformly, because the measuring pieces 7 constantly engage at different places with the pinion 23 and with the detent 27.

'1 claim 1. in a tachometer of the character de guide rods conjointly' rota able about a oommen axis, a cylindrical, toothed measuring piece slidable along and rotatable on each of said rods, 11 spring-influenced arm, a cylindrical, toothed detent rotatably mounted on said arm and adapted to arrest the mess uring pieces in turn, and means for intermittently rotating said guide rods about said axis.

In testimony whereof, I affix my signature in the presence of two witnesses.

DTTO ABEREGG.

VRDBSSESS FRIEDRICH Kareem, r4 A'F'll ANAlL Ls one. 

